Sourced from pyasn1's releases.
Release 0.6.4
This is a security release.
- CVE-2026-59885 (GHSA-8ppf-4f7h-5ppj): Fixed quadratic time complexity in the OBJECT IDENTIFIER and RELATIVE-OID decoders. A small crafted substrate encoding many arcs could consume excessive CPU.
- CVE-2026-59884 (GHSA-m4p7-r5rc-7g4j): Limited BER long-form tag IDs to 20 octets (140 bits). Unbounded tag IDs allowed a crafted substrate to consume excessive CPU and memory.
- CVE-2026-59886 (GHSA-hm4w-wwcw-mr6r): Fixed excessive memory and CPU consumption in
Real.__float__()for values with large base-10 exponents.- Pinned PyPI publish GitHub Action to an immutable commit.
All changes are noted in the CHANGELOG.
Sourced from pyasn1's changelog.
Revision 0.6.4, released 08-07-2026
- CVE-2026-59885 (GHSA-8ppf-4f7h-5ppj): Fixed quadratic time complexity in the OBJECT IDENTIFIER and RELATIVE-OID decoders. A small crafted substrate encoding many arcs could consume excessive CPU. Arcs are now accumulated in linear time; decoded values are unchanged (thanks for reporting, tynus2)
- CVE-2026-59884 (GHSA-m4p7-r5rc-7g4j): Limited BER long-form tag IDs to 20 octets (140 bits), matching the OID arc limit introduced in 0.6.2. Unbounded tag IDs allowed a crafted substrate to consume excessive CPU and memory; longer tag IDs are now rejected with PyAsn1Error. Also fixed Tag and TagSet repr() failing on huge tag (thanks for reporting, mikeappsec) IDs due to the integer-to-string conversion limit (Python 3.11+)
- CVE-2026-59886 (GHSA-hm4w-wwcw-mr6r): Fixed excessive memory and CPU consumption in Real.float() for values with large base-10 exponents. Conversion no longer materializes huge intermediate integers; values too large to represent as a Python float raise OverflowError promptly, and prettyPrint() renders them as '' as before. Also fixed base-10 mantissa normalization to use exact integer arithmetic; mantissas larger than 2**53 could previously lose precision through float division (thanks for reporting, gvozdila)
- Pinned PyPI publish GitHub Action to an immutable commit [pr #113](pyasn1/pyasn1#113)